HVAC Residential vs Commercial HVAC

Question 1

What is the typical cooling capacity range for residential central air conditioning systems?

Accepted Answer

1.5 to 5 tons (18,000-60,000 BTU/hr)

Answer

Residential central air conditioning systems typically range from 1.5 to 5 tons (18,000-60,000 BTU/hr). Smaller homes may use 1.5-2 tons; larger homes up to 5 tons. Systems above 5 tons enter light commercial territory.

Question 2

What is the primary difference between a residential split system and a commercial rooftop unit (RTU)?

Accepted Answer

RTUs are self-contained (all components in one unit); split systems have separate indoor and outdoor units

Answer

A commercial rooftop unit (RTU) is self-contained — compressor, condenser, evaporator, and controls are all in one outdoor unit. Residential split systems have a separate outdoor condensing unit and indoor air handler connected by refrigerant lines.

Question 3

What type of control system is most common in residential HVAC versus commercial HVAC?

Accepted Answer

Residential: Simple thermostats; Commercial: Building Automation Systems (BAS) with DDC controls

Answer

Residential HVAC relies on simple programmable or smart thermostats with on/off or basic two-stage control. Commercial HVAC typically uses full Building Automation Systems with DDC controllers, VAV boxes, sensors, and centralized monitoring/control.

Question 4

What is 'zoning' in HVAC systems and how does it differ between residential and commercial applications?

Accepted Answer

Residential zoning uses dampers and multiple thermostats in one system; commercial uses separate AHUs or VAV systems serving multiple zones

Answer

Zoning divides a building into areas with independent temperature control. Residential zoning uses motorized dampers and a zone controller with multiple thermostats on one system. Commercial buildings use VAV systems, multiple AHUs, or fan coil units to independently control many zones.

Question 5

What refrigerant is required in new residential split systems sold in the US starting January 1, 2025?

Accepted Answer

R-32 or R-454B (or other low-GWP alternatives)

Answer

Due to the AIM Act phasedown of HFCs, EPA regulations require new residential and light commercial AC systems to use refrigerants with GWP below 750, effective January 1, 2025. R-454B (GWP ~466) and R-32 (GWP 675) are the primary replacements for R-410A.

HVAC - Heating, Ventilation, and Air Conditioning Practice Test

HVAC - Heating, Ventilation, and Air Conditioning Practice Test

HVAC Residential vs Commercial HVAC